Residual-free removal solutions for films
Publication Date: 2017-May-12
The IP.com Prior Art Database
The idea proposed herein addresses the problem of achieving a residual-free removal of a high tack, thin and pliable polyurethane film (herein called "base film") that may for example be used for application on the body of a vehicle.
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Residual-free removal solutions for films The idea proposed herein addresses the problem of achieving a residual-free removal of a high tack, thin and pliable polyurethane film (herein called “base film”) that may for example be used for application on the body of a vehicle. The idea is to laminate a second supporting layer onto the film (herein called “removal film”) thereby enhancing the mechanical stability of the resulting film stack and allowing the base film to be peeled off. The key feature of the idea is to use a mechanical support layer (removal film) with similar mechanical properties as the base film and to use a high performance adhesive. In peeling the two-layered film stack, the base film is slowly but evenly removed from the substrate (e. g. body of a vehicle) without traces of adhesive or tearing of the film.
Figure 1: Residual-free peel of base film applied to a painted metal sheet with the help of an additional removal film.
In order to avoid cost-intensive masking procedures for bi-tone colorations of vehicle, automotive customers are asking for colored film solutions to be applied for example to the roof of a car. Very much like the current car paint solutions, such films need to endure at least 10 years of exposure to the elements without significant visual degradation. One aspect of achieving this is to use extremely pliable, thin polyurethane films equipped with high tack adhesives. The challenge associated with these polyurethane films is that they are very hard to remove once applied, as they tear easily and in tiny strips. Residual-free removal of one such film applied to a car roof takes an experienced worker more than 5 hours. The idea proposed herein solves this problem in an easy to apply, low-tech approach. Furthermore, due to the gentle removal process, it is suitable for film removal close to sensitive parts like car antennas, other laminated areas (blackout films) or rear view mirrors. Finally, unlike film/adhesive removal with pressurized media, the proposed solution is unlikely to increase underlying damages in the car paint, e.g. scratches or impact damages. The basic idea is to perform a >90° peel of the base film from a painted substrate (see Figure 2). If the peel is done correctly, the base film takes away the adhesive layer, leaving a clean surface below. However, a problem may occur if the base film alone cannot withstand the required peel force and tears off easily, which may then result in millimeter-sized strips coming off the substrate. The idea is to improve the mechanical robustness of the base film by applying a second film layer on top of the base film. The resulting film stack is sufficiently robust to allow manual peel without tearing of the base film. If the adhesion of the base film to the substrate is very high, the removal film needs superb...